Ratchet and pawl drive magnetic motor



July 23, 19.63 c. RUBY 3,098,940

RATCHET? AND PAWL DRIVE MAGNETIC MOTOR Filed Oct. 25, 1961 2 Sheets-Sheet 1 INVENTOR Charles Ruby BY ATTORNEY Theodor Haw W July 23, 1963 c. RUBY RATCHET AND PAWL DRIVE MAGNETIC MOTOR 2 Sheets-Sheet 2 Filed 001;. 23, 1961 INVEN'IOR Charles Ruby BY ATTOR WA 0 Theodore Hafner United States Patent 3&98340 RATCHET AND PAWL DRIVE MAGNETIC MOTGR Charles Ruby, Paris, France, assignor to Societe An'onyme dite: LUsine a ldees, Sartrouville, France, a French society Filed Oct. 23, 1961, Ser. No. 146,920 Claims priority, applicationFrance (let. 24, 196i) 8 Claims. (Cl. 310-22) Various types of electro-magnetic motors are known which comprise a vibrating strip co-operating with a ratchet wheel and designed, more particularly, to operate childrens toys. Generally, the vibrating strip is excited by an electro-magnet energized by continuous current, the device being supplied through a switch providing alternate attraction and repulsion of the vibrating strip.

Always, in their application more particularly to the operation of childrens toys, particularly the propulsion of .model cars, such motors are somewhat cumbersome and,

in other cases, do not permit the attainment of high speeds for driving the wheels. This disadvantage is particularly troublesome when the cars are models of racing cars which to provide an interesting game must travel at substantial speed.

The present invention has for an object a new electromagnetic motor, particularly useful for driving childrens toys, overcoming the inconveniences indicated above and providing many other advantages.

The electro-magnetic motor comprises an electro-magnet driving system comprising a pawl and ratchet wheel. According to the invention the driving system of the motor shaft comprises at least two ratchet wheels keyed to the shaft, the teeth of one of the wheels being angularly displaced relative to that of the other wheel. At least two vibrating strips are fixed to the armature of the electro-magnet and co-operate respectively with the teeth of each of the ratchet wheels.

According to a preferred embodiment of the invention the ratchet wheels have the same diameter and the vibrating strips comprise a fork of which the teeth are of the same length.

In a particular construction, the teeth of the ratchet wheels may be angularly displaced relative to one another by an angle equal to l/n of the angle between two consecutive teeth of a wheel, n beingthe number of ratchet wheels. The orientation of the various ratchet wheels relative to one another is such that there is at least one tooth every l/n of the angle between two consecutive teeth of a wheel.

According to another feature of the invention, the electro-magnet is energized by alternating current and the dimensions of its armature and the vibrating strips are calculated to ensure their vibration in synchronism with the frequency of the current.

According to a particular embodiment, the moving part of the electro-magnet consists of a leaf secured to the frame of the motor and the end of a return spring, also fixed to the frame, comprises a resilient stop for the moving part of the electro-magnet when this is not attracted. The point of contact between the end of the spring and the moving part of the electro-magnet is located adjacent a node of vibration of the latter.

The invention and its advantages will be better understood and at the same time the different features of one embodiment will appear in the course of the following description with reference to the accompanying drawings in which:

FIG. 1 is a longitudinal diagrammatic sectional view of a small car equipped with a motor according to the invention, the body of the car not being shown,

FIG. 2 is a section along the line IIII of FIG. 1,

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FIG. 3 is a section along the line IIIIII of FIG. 2.

FIG. 4 shows in perspective part of FIG. 1, and es pecially its vibrating part in greater retail.

Referring more particularly to FIG. 1, this shows the chassis 1 of a small car in which is mounted the yolk 2 of an electro-magnet excited by a winding 3-. Preferably, for reasons which will appear below, the yolk of the electro-magnet has three limbs, the central limb carrying the exciting winding 3. A vibrating strip 4 is secured on the chassis 1 by means of rivets S and carries an armature 6 which can be attracted by the yolk of the electro magnet. The vibrating strip 4 co-operates at its free end 4a with a plurality of ratchet wheels of which the characteristics are given below.

A spring 7 is also secured by the rivets 5 on the chassis of the car and is adapted to bear upon the vibrating strip 4. The length of the return spring is so chosen that the bearing point on the vibrating strip is situated in the neighbourhood of a node of vibration of the strip.

Referring now to FIGS. 2 and 3 the details of the arrangement of the ratchet wheels and the vibrating strip can be seen. The end 4a of the vibrating strip has the form of a fork with four teeth 4b, 4c, 4d, 4e of as nearly the same length as possible. The teeth co-operating with the teeth of the ratchet wheels Sb, 8c, 8a, 82 are fixed on an axle 9 supporting the wheels 12 of the vehicle.

As can be seen from FIGS. 2 and 3 the ratchet wheels have identical teeth, but are angularly displaced with respect to one another. In the construction being described each ratchet wheel comprises ten teeth which consequently are spaced by 36 and the teeth of the wheel 30, for example, are angularly displaced relative to teeth of the wheel 8b by 9. In the same way the teeth of the wheel 8d and the teeth of the wheel 8e are respectively displaced by 9 relative to the teeth of the wheel and of the wheel 8d. By this artifice it is possible to increase the number of teeth without using a ratchet wheel of excessive diameter. It is known, of course, that to obtain substantial speeds the ratchet wheel used should have a diameter as small as possible relative to the diameter of the wheels of the vehicle.

The electro-magnet shown in FIG. 1 is excited by an alternating current supplied to two conductors arranged on the car track, the current being collected by two shoes (not shown) electrically connected to the winding 3. The dimensions of the vibrating strip 4 are determined by a simple calculation, so that the strip 4- vibrates in synchronism with the frequency of the current. FIG. 4 shows strip 4 in greater detail and in perspective. When current flows the strip 4 is attracted, then repelled, as a result of the elasticity of the leaf. If the amplitude of the current which passes through the winding 3 is small, the force of attraction on the strip is also small. The impulse given to the motor shaft by the action of one of the strip teeth, by the tooth 4b for example, on the ratch wheel tooth 8b is weak and the axle 9 only turns through a small angle whilst the current flows in the winding 3. For the following impulse, the tooth 4c is opposite the tooth of the ratchet Wheel 80, separated angularly by 9 relative to the tooth 4b acted upon during the previous impulse. It follows, therefore, that the car is moved slowly on its track.

It, to the contrary, the amplitude of the current through the wind 3 is increased, the force which is applied by the tooth 412, for example, on one of the teeth of the ratchet wheel 8b is equally strong and permits a greater rotation of the axle 9 than 9 whilst cuurrent is flowing in the winding 3. During the following impulse one of the teeth 4b, 4c, 4d, 4e comes opposite one of the teeth of the wheels 8]), 8c, 8d, 3e assuring in turn an appreciable rotation of the axle 9 during the flow of current through the winding.

It will be seen that the arrangement of the ratchet Wheels according to the invention increases the likelihood of one of the teeth of the vibrating strip coming opposite one lot the teeth of a ratchet wheel and, consequently, avoids the liklihood of vibrations of the strip 4 not being effective to produce propulsive drive.

In practice with ratchet wheels of a diameter of approximately one-quarter :of an inch and with car wheels of a diameter of approximately one inch, one can obtain, by means of a motor according to the invention, speeds of the order of ten feed per second. Moreover, it should be appreciated that the presence of a return spring 7 also contributes to the improvement obtained from motors according to the invention. In fact, the resilient energy freed at the moment when the strip 4 is released by the electro-magnet is partially recovered by the spring 7 which, in its turn supplies it to return the strip 4 at the moment when it is again attracted by the electro-magnet. It is thus possible to make cheaply and with mechanical an interesting car racing game.

There will now be described several details of a preferred embodiment of the invention. Referring to FIGS. 2 and 3 it will be seen that the ratchet Wheels 8b and 8c are parts of a single member 1%), preferably in moulded plastic. In the same way the ratchet wheels 8d and 8e are parts of a single member 11. The twopieces and 11 are similar and each comprises an equal number of teeth displaced angularly by 9". Furthermore, on one of their side faces they have assembly pins 10a and 11a adapted to enter respectively corresponding holes, holes 101; and 11b. The positions of the pins 10a and 11a and the holes ltlb and 11b is determined so that the two adjacent teeth 8c and 80', for example, are displaced by 9 in the same direction as the displacement of the teeth 8b and 80.

Moreover, slots lite and He are provided in the members It and 11 where the axle 9 passes through them for the purpose of securing the ratchet wheels on the axle. In practice, in known manner, the wheels .12 are angularly positioned on the axle by clips 9a so that the ratchet wheels can be slid along the axle into their positions. The slots 10c and 110 allow for the sliding of the clips 911. At the same time, the axle 9 'has clips 91) and in the members 10 and 11 are provided blind slots 10d and 11d. 'Ihese slots engage with the clips 9b and the pins 16a and 11a are fixed by means of a glue, for example in the corresponding holes 10b and 11b. There is thus obtained complete rotational and longitudinal locking of the ratchet wheels ensuring the correct drive of the axle 9.

It will be appreciated that the invention is not limited to the construction which has been described and various modifications will be apparent; particularly, dependent upon the dimensions of the toy a smaller or greater number of ratchet wheels or groups :of ratchet wheels can be used. Also, the invention can be utilized in many applications, but it is particularly useful for the propulsion of miniature cars.

I claim:

1. An electro-magnetic motor comprising an elect-romagnet having an armature, at least two vibratable strips secured to said armature, each of said strips having a toothed end, a shaft, and at least two ratchet wheels fixed on said shaft, said ratchet wheels each having a plurality of teeth, the teeth of one of said ratchet Wheels being angularly displaced relative to the teeth of the other of said ratchet wheels, the toothed end of one of said strips being movable by said armature to rotate one of said ratchet wheels and the toothed end of the other of said strips being movable by said armature to rotate the other of said ratchet wheels.

2. A motor according to claim 1, wherein said ratchet wheels are the same diameter and said vibratable strips consist of a forked member of which the teeth are of the same length.

3. A motor according to claim 1, wherein the teeth of said ratchet wheels are angularly displaced relative to one another by an angle equal to l/n of the angle between two consecutive teeth of any given wheel, where n is the number of wheels, whereby there is a ratchet wheel tooth at every 1/ n of the angle between two consecutive teeth of any given wheel.

4. A motor according to claim 1, wherein said ratchet wheels are of moulded plastic material and on at least one of their side faces have an assembly pin and a hole, the pin of each ratchet wheel fitting in the hole of an adjacent ratchet wheel.

5. A motor according to claim 1, wherein each pair of adjacent ratchet wheels are formed as a single member, each of said members having a side face with a hole therein and a pin extending therefrom, the pin of each of said members fitting in the hole of the adjacent member.

6. A motor according to claim 1, wherein said armature and said vibrating strips are resonant at sixty cycles per second.

7. A motor according to claim 1, further comprising a return spring, said return spring being a spring strip having one end in contact with a vibratable strip at a nodal point of vibration of the said vibratable strip.

8. In electro-magnetic shaft propulsion means, an electromagnet, said electro-magnet having a cooperating armature adapted to vibrate when said electro-magnet is energised with alternating current, a pawl, said pawl having a plurality of spaced teeth and being secured to said armature for vibration therewith, and a plurality of ratchet Wheels equal in number to said spaced teeth, said ratchet wheels each having a plurality of ratchet teeth and being fixed on the shaft to be propelled With the ratchet teeth of each ratchet wheel angularly displaced relative to the ratchet teeth of the other ratchet wheels.

References Cited in the file of this patent UNITED STATES PATENTS 2,943,512 Nicolous July 5, 1960 

8. IN ELECTRO-MAGNETIC SHAFT PROPULSION MEANS, AN ELECTRO-MAGET, SAID ELECTRO-MAGNET HAVING A COOPERATING ARMATURE ADAPTED TO VIBRATE WHEN SAID ELECTRO- MAGNET IS ENERGISED WITH ALTERNATING CURRENT, A PAWL, SAID PAWL HAVING A PLURALITY OF SPACED TEETH AND BEING SECURED TO SAID ARMATURE FOR VIBRATION THEREWITH, AND A PLURALITY OF RATCHET WHEELS EQUAL IN NUMBER TO SAID SPACED TEETH, SAID RATCHET WHEELS EACH HAVING A PLURALITY OF RATCHET TEETH AND BEING FIXED ON THE SHAFT TO BE PROPELLED WITH THE RATCHET TEETH OF EACH RATCHET WHEEL ANGULARLY DISPLACED RELATIVE TO THE RATCHET TEETH OF THE OTHER RATCHET WHEELS. 